ASTM D4438-85(2001)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
e1
Designation:D4438–85(Reapproved2001)
Standard Test Method for
Particle Size Distribution of Catalytic Material by Electronic
Counting
This standard is issued under the fixed designation D 4438; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Editorial changes were made throughout in October 2001.
1. Scope forced through a restricting aperture. Each passing particle is
recordedonanelectroniccounter,andthedataareaccumulated
1.1 This test method covers the determination of particle
according to selected particle size intervals for subsequent
size distribution of catalyst and catalyst carrier particles using
processing.
an electroconductive sensing method and is one of several
3.2 The instrument response is proportional to liquid dis-
valuable methods for the measurement of particle size.
placement by the particle volume. Equivalent spherical diam-
1.2 The range of particle sizes investigated was 20 to 150
eter is commonly used to express the particle size.
µm (see IEEE/ASTM SI 10) equivalent spherical diameter.
The technique is capable of measuring particles above and
4. Significance and Use
below this range. The instrument used for this method is an
4.1 This test method can be used to determine particle size
electric current path of small dimensions that is modulated by
distributionsformaterialspecifications,manufacturingcontrol,
individual particle passage through an aperture, and produces
and research and development work in the particle size range
individual pulses of amplitude proportional to the particle
usually encountered in fluidizable cracking catalysts.
volume.
1.3 This standard does not purport to address all of the
5. Apparatus
safety concerns, if any, associated with its use. It is the
5.1 Electronic Particle Counter, with sample stand and
responsibility of the user of this standard to establish appro-
stirring motor.
priate safety and health practices and determine the applica-
5.2 Aperture Tubes, with varying diameters. The diameter
bility of regulatory limitations prior to use.
required is dependent upon the particle size distribution of the
2. Referenced Documents sample. Generally, any given tube will cover a particle size
range from 2 to 40 % of its aperture diameter.
2.1 ASTM Standards:
2 5.3 Ultrasonic Tank, 100 W.
D 1193 Specification for Reagent Water
5.4 Beaker, 100-mL.
E 177 Practice for Use of the Terms Precision and Bias in
3 5.5 Graduated Glass Pipet, 5-mL.
ASTM Test Methods
5.6 Wash Bottles.
E 691 Practice for Conducting an Interlaboratory Study to
3 5.7 Membrane Filtering Device with 0.22-µm filters.
Determine the Precision of a Test Method
5.8 Round-Bottom Sample Beakers, 250-mL.
IEEE/ASTM SI 10 Standard for Use of the International
4 5.9 Micro-Riffler or Chute Riffler.
System of Units (SI): The Modern Metric System
6. Reagents
3. Summary of Test Method
6.1 Purity of Reagents—Reagent grade chemicals shall be
3.1 Acarefully dispersed, dilute suspension of the sample in
used in all tests. Unless otherwise indicated, it is intended that
a beaker filled with an electrolyte is placed in the counting
all reagents shall conform to the specifications of the Commit-
position on the instrument sample stand. The suspension is
tee onAnalytical Reagents of theAmerican Chemical Society,
where such specifications are available. Other grades may be
This test method is under the jurisdiction of ASTM Committee D32 on
Catalysts and is the direct responsibility of Subcommittee D32.02 on Physical-
Mechanical Properties. Apparatus used in this study are detailed in Research Report RR: D32–1011.
Current edition approved March 18, 1985. Published May 1985. “Reagent Chemicals,American Chemical Society Specifications,”Am. Chemi-
Annual Book of ASTM Standards, Vol 11.01. cal Soc., Washington, DC. For suggestions on the testing of reagents not listed by
Annual Book of ASTM Standards, Vol 14.02. the American Chemical Society, see “Analar Standards for Laboratory U.K.
Annual Book of ASTM Standards, Vol 14.04. Chemicals,” BDH Ltd., Poole, Dorset, and the “United States Pharmacopeia.”
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
e1
D4438–85 (2001)
used, provided it is first ascertained that the reagent is of 7.4.4 Remove the beaker (from 7.4.1) from the sampling
sufficiently high purity to permit its use without lessening the stand. Flush the outside of the aperture tube, the stirrer, and
accuracy of the determination. outer electrode. Place the sample and beaker from 7.4.3 in the
6.2 PurityofWater—Unless otherwise indicated, references sampling stand. Adjust the stirring blades close to the bottom
to water shall be understood to mean reagent water conforming of the round-bottom beaker so that they effectively sweep the
to Specification D 1193, Type II. bottom of the beaker again. Increase the stirrer speed moder-
6.3 Electrolyte—Dissolve 10.0 g of reagent grade sodium ately. Check for particle settling by visually observing the
chloride (NaCl) in 1 Lof distilled or deionized water and filter stirring system with a flashlight and viewing the surface
twice through a 0.22-µm filter. perpendicular to the bottom. If particles are observed settling,
increase stirring rate without generating air bubbles or increase
NOTE 1—Commercially available Electrolyte solution of the same
the electrolyte viscosity, or both.
concentration can also be used, but should be filtered for apertures smaller
than 100 µm.
NOTE 3—Electrolyteviscositycanbeincreased,forexample,byadding
filtered glycerol up to 30 % by volume.
6.4 WashWater—Distilledordeionizedwater,twicefiltered
through a 0.22-µm filter. Electrolyte may also be used as wash
7.4.5 Initiate a preliminary count and check that the total
water.
count is in the range suggested in the manufacturer’s
...